1. Field of the Invention
The invention relates generally to genetic analysis and more specifically to genetic analysis related to canine gender.
2. Background Information
DNA-based techniques have become accepted methods for the determination of gender. The use of DNA for gender determination has been particularly effective in situations where sex is difficult to determine accurately by visual or manual examination, such as in certain avian species, and in circumstances where visual inspection is not possible, and gender must be determined from a biological sample alone.
For example, Griffiths, et al. (1996), U.S. Pat. No. 5,508,165 (Halverson et al. '165), U.S. Pat. No. 5,679,514 (Baker), and U.S. Pat. No. 5,707,809 (Halverson et al. '809) disclose methods for determining the sex of many avian species by DNA techniques. These methods amplify fragments specific to avian sex chromosomes. In some other species, chromosomal regions corresponding to the amelogenin gene have been used to develop DNA-based sexing tests. Amelogenin is involved in the production of tooth enamel and in many mammals there exists a copy of the gene on the X chromosome (AMELX) and another on the Y chromosome (AMELY). Differences in these homologs have allowed the development of gender tests in which different sized fragments are simultaneously amplified from X and Y chromosomes using a single set of primers. These tests have been developed for human (Sullivan et al. 1993), equine (Hasegawa et al. 2000) and bovine DNA (Chen et al. 1999). Although in some cases these primers are not 100% specific to the species being sex-typed and will amplify fragments from other species (Buel et al. 1995), they are unique enough to be only useful as gender markers for the species for which they are developed. The markers developed for human gender testing, for example, do not distinguish male and female canines.
The gender determination of an individual dog using DNA-based techniques would be an important quality control step in applications that utilize canine genotyping. Most canine registries request that information about an individual dog, including gender, be provided by the owner upon registration. In some cases DNA samples, in the form of cheek swabs, are also provided for identity determination or parentage verification. Since the individual dog is not available for visual inspection, the determination of gender from DNA isolated from the submitted sample would verify accuracy of the submitted gender information by the registrant, and improves the integrity of data that becomes part of the registry database.